1. Field of the Invention
The invention is directed to a process for the warping of threads on a warping machine having a drum provided with a cone, into a plurality of sequentially following warp bands. These bands are fed by a slide, moveable axially relative to the drum. During the warping of the first band, after a predetermined initial phase, a correction of the prescribed slide advancement occurs, based upon the target/actual comparison of an aspect parameter characterizing the form of the winding of the band. During the warping of the sequential bands in the initial phase of the prescribed slide advancement and thereafter the corrected slide advancement is copied.
The invention is further directed to a warping machine for carrying out this process, having: a drum with a cone; a slide displaceable relative to the drum for providing warp bands (and having an adjustable slide advancement drive); a measuring arrangement for the determining the above noted aspect parameter; an arrangement for the correcting the slide advancement drive in response to the target/actual comparison of the aspect parameter; and a storage means for storing data obtained from the first band wind and the slide advancement and copying the same during the following winds.
2. Discussion of the Prior Art
DE-OS 34 32 276 discloses a conical warping machine of the foregoing type, wherein the threads are pulled off a spool creel and wound onto a self-rotating drum. To correlate the band wind to the provided cone, the drum and a slide (carrying a thread reed) are axially displaceable relative to each other.
After a predetermined initial phase which is determined by a predetermined number of rotations of the drum, the set-back timing path is measured by a radially displaceable contact roller and compared with the corresponding target value. At the occurrence of a deviation therefrom, a deviation correcting change occurs in the slide advancement. In the subsequent winds the initial phase of the slide advancement and the subsequently corrected slide advancement is copied.
DE AS 25 10 517 suggests another mode. The slide advancement is positively coupled to a contact roller so that the slide advancement increases proportionately to the increase in wind diameter. However, there is no control on whether the first band wind has the same inclination to the cone. Furthermore, the wind is continually measured and recorded relative to the number of rotations. During the warping of the subsequent bands corresponding curves are drawn and compared with a curve of the first band. When deviation occurs, the contact pressure of the contact roller is altered to the extent that the thread tension corresponds to the correct value of the first band.
DE OS 39 13 381 describes a procedure for the formation of a warp beam having a cylindrical wind. A rotational counter transmits the number of rotations. A measuring device determines the winding diameter. Both of these should occur in a predetermined target relationship. If the actual relationship does not correspond thereto, without measuring the warp thread tension, the difference should be compensated for by altering the provision speed of the thread sheet; for example by raising the rotational speed of the turning rollers. This correction can occur after a predetermined number of rotations.
This reference does not concern itself with the problems inherent in conical warping. It does not in fact progress beyond that which was disclosed in DE AS 25 10 517 in conjunction with conical warping.
Accordingly, there is a need for an improved mode for warping threads in a more even manner than was available heretofore.